EXPLORER 7100 1.0 Meter, Auto-Deploy Drive-Away Antenna System

Total Page:16

File Type:pdf, Size:1020Kb

EXPLORER 7100 1.0 Meter, Auto-Deploy Drive-Away Antenna System EXPLORER 7100 1.0 Meter, Auto-Deploy Drive-Away Antenna System 2013 Data Sheet The most important thing we build is trust Markets • Military • Homeland Security • Emergency Response • Law Enforcement • Media: Live Streaming Video, TV Broadcasting • Telemedicine: Critical Medical Information Transmission • Mobile Insurance Claims & Settlements • Remote Office Communications • Energy and Mining Applications • Continuity of Business Operations • Remote Business Videoconferencing Ku-band Configuration • Internet Cloud Services: Voice, Radio, Data, Fax, Live Broadcast EXPLORER 7100 Reflector Size 1.0m Resin Fiber Composite The EXPLORER 7100 is a 1.0m drive-away antenna, for Ku or Ka-band operations. The EXPLORER 7000 series also inclues 1.2m and 1.8m Optics Offset, Prime Focus, 0.8 F/D configurations. Operating in the alternative frequency band is achieved Mount Geometry 3-Axis, Elevation over Azimuth by simply exchanging the feed assembly using an easy-to-remove feed mounting plate. This auto-deploy system allows personnel with minimal Polarization Ku-band: Linear with Motorized Rotation satellite experience to easily configure and operate this terminal Ka-band: RHCP or LHCP enabling the user to access any broadband application over satellite. Mechanical The EXPLORER 7100 is pending Eutelsat type approved for KA-SAT Positioner Cable Drive operations on the Tooway Network. Travel Velocity Azimuth 400° or ± 200° Elevation 0-90° antenna boresight (mechanical) Standard limits at 5° to 65° (CE Approval) or 5° to 90° (operational) Polarization ±95° Slewing & Deploying 2° per second Manual Jog 1.0° or 0.2° per second KA-SAT Configuration Weights & Measures System Features Approx. Weight 45 kg (100 lbs) without BUC / LNB • Rugged, Reliable 1.0m dual-band (Ku/Ka) Drive-Away Antenna Approx. Length 157.4 cm (62”) • Solid Resin Fiber Composite Reflector Stowed Height* 34.3 cm (13.5”) • Standard Ka-band configuration includes 4W transmit and receive Deployed Height* integrated assembly (TRIA) and ViaSat Surfbeam 2 Professional 152.4 cm (60”) Modem (*with loadframe) Antenna Control Weight: 2 kg (4.5 lbs.) • Mechanical Drive systems including Zero-Backlash Az/El Cable Unit (1RU) Size: 23 L x 26 W x 6.4 H cm (9”x 10.3”x2.5”) Drive with Power Supply and TracLRI • Precision Polarization Drive in Ku-band configuration Handheld Display Unit Weight: 0.22 kg (0.5 lbs) • WR-75 Flex WaveGuide to block upconverter (BUC) interface Size: 14 L x 8.3 W x 3.5 H cm (5.5” x 3.3” x 1.4”) in Ku-band configuration Shipping Crate 190 x 120 x 78 cm (75”x47”x31”), 125 kg (275 lbs.) • Inclined orbit satellite tracking option Dimensions 1.78 m3 (63 ft3) • Manual override capability for emergency use Related Products: EXPLORER 7120, 7180 www.cobham.com EXPLORER 7100 1.0 Meter, Auto-Deploy Drive-Away Antenna System Antenna Characteristics Ku-band Ka-band (Eutelsat) About EXPLORER Products Receive Transmit Receive Transmit Cobham SATCOM Land offers a diverse array of turn-key Frequency (GHz) 10.95 -12.75 13.75 -14.5 19.7 - 20.20 29.5 - 30.0 satellite terminals that fulfill critical communications needs and reduce system configuration requirements for Antenna Gain (dBi ± 0.2) 39.9 41.4 44.5 48.0 end users. The solutions we provide offer a wide variety VSWR 1.3:1 1.3:1 1.3:1 1.3:1 of data rates in multiple frequency bands including L, Ku, Cross Pol Isolation (dB) Ka, and X-bands. Systems are available as manual, or auto- On-Axis 30 35 21.5 21.5 deploy configuration, and are organized in drive-away, Cross Pol Isolation (dB) fly-away and comm-on-the-move (COTM) families. When within 1dB beamwidth 28 30 - - traditional communication technologies are unavailable Feed Port Isolation - or fail, our products provide high quality VoIP, RoIP, Tx to Rx (dB) 35 80 w/filter - - FAX, data, and multimedia communications that work efficiently across satellite links. We specialize in assisting Beamwidth (degrees) partners with integrated end-to-end solutions for rapid - at -3dB 1.8 1.5 1.1 0.7 deployment to support disaster recovery, continuity of - at -10dB 3.2 2.8 1.9 1.3 operations and other mission critical applications. Antenna Noise Temp. (°K) at 20° Elevation 55° 107° Cobham Antenna Controller G/T - Comm @ 30° EL, Industry standard setting one-button auto-deploy Midband (dB/°K) 19.5 20.4 operation with automatic satellite acquisition and cross- pol adjustment, integrated GPS, GLONASS, Compass, Radiation Pattern Compliance FCC §25.209, ITU-R S.580 ITU-R S.580 Level Sensors and user configurable satellite selection for primary and secondary satellites. The controller inclues a Linear Orthogonal Std RHCP or LHCP Polarization Optional Co-pol (auto selectable) web-based graphical user interface accessory that allows the user to easily configure and remotely monitor satellite Standard BUC Options 4W, 8W, 16W 4W TRIA auto-acquisition operations using a standard web browser. EIRP with Standard BUC Options (dBw) 47.4, 50.4, 53.4 54 Specifications Subject to Change Without Notice Environmental Wind Speed Operational (anchored) 72 km/h (45 mph) Survival (anchored) 80.5 km/h (50 mph) (anchored/stowed) 161 km/h (100 mph) Fly & Drive Option Temperature Operational -30° to +51°C (-22° to 125°F) Survival -40° to +60°C (-40° to 140°F) Rain <100 mm/hr Humidity 0 to 100% (condensing) Deployed Position (in inches [cm]) Electrical RF Rx and Tx: Type F (75-ohm) connectors on both ends Two RG6 Coax 9.14m (30 ft) Interfacility Link One Control Cable 9.14m (30 ft) Motors 24VDC Servo w/ Optical Encoder, Constant Torque Controller (1RU) Power 90 - 264 VAC, 50/60Hz Single Phase Stowed Position (in inches [cm]) Supply 300W standard; 1000W option available Motors Active – 250 Watts EXPLORER7100-3 © 2013 All Rights Reserved Power Consumption Motors Idle – 30 Watts For further information please contact: BUC Mounting Feed Boom (maximum weight 7.3 kg / 16 lbs.) Cobham SATCOM Land 1551 College Park Business Center Road Waveguide 90° WR75 Waveguide Rotary Joint @ Feed TX Input Orlando, Florida 32804 USA Tel: + 1-407-650-9054 Manual Drive Handcrank on Az & El; Knob on Pol Fax: + 1-407-650-9086 www.cobham.com.
Recommended publications
  • Resolving Interference Issues at Satellite Ground Stations
    Application Note Resolving Interference Issues at Satellite Ground Stations Introduction RF interference represents the single largest impact to robust satellite operation performance. Interference issues result in significant costs for the satellite operator due to loss of income when the signal is interrupted. Additional costs are also encountered to debug and fix communications problems. These issues also exert a price in terms of reputation for the satellite operator. According to an earlier survey by the Satellite Interference Reduction Group (SIRG), 93% of satellite operator respondents suffer from satellite interference at least once a year. More than half experience interference at least once per month, while 17% see interference continuously in their day-to-day operations. Over 500 satellite operators responded to this survey. Satellite Communications Overview Satellite earth stations form the ground segment of satellite communications. They contain one or more satellite antennas tuned to various frequency bands. Satellites are used for telephony, data, backhaul, broadcast, community antenna television (CATV), internet, and other services. Depending on the application, each satellite system may be receive only or constructed for both transmit and receive operations. A typical earth station is shown in figure 1. Figure 1. Satellite Earth Station Each satellite antenna system is composed of the antenna itself (parabola dish) along with various RF components for signal processing. The RF components comprise the satellite feed system. The feed system receives/transmits the signal from the dish to a horn antenna located on the feed network. The location of the receiver feed system can be seen in figure 2. The satellite signal is reflected from the parabolic surface and concentrated at the focus position.
    [Show full text]
  • IBUC) Operation Manual
    Intelligent Block Upconverter (IBUC) Operation Manual No part of this manual may be reproduced, transcribed, translated into any language or transmitted in any form whatsoever without the prior written consent of Terrasat Communications, Inc. © Copyright 2006 Terrasat Communications, Inc. O&M – 10770-0001 Revision A 235 Vineyard Court, Morgan Hill, CA 95037 Phone: 408-782-5911 Fax: 408-782-5912 www.terrasatinc.com 24-hour Tech Support: 408-782-2166 Table of Contents ______________________________________________________________________ 1. Introduction Overview ………………………………………………………………………1-1 Reference documents ............................................................................ 1-2 Furnished Items...................................................................................... 1-4 Storage Information ................................................................................ 1-6 Warranty Information .............................................................................. 1-6 Warranty Policy ...................................................................................... 1-8 2. IBUC Systems: Description Functional Description ............................................................................ 2-1 System Configurations ........................................................................... 2-2 System Block Diagrams ......................................................................... 2-3 3. IBUC Systems: Component Descriptions Intelligent Block Upconverter (IBUC) .....................................................
    [Show full text]
  • To Support Production of Linearized Block Up-Converters (L-Bucs) Katalin Frolio, Student Member, IEEE and Allen Katz, Fellow, IEEE
    1 MTT-S Undergraduate/Pre-Graduate Scholarship Project Report Design and Verification of Specialized Test Equipment (STE) to support production of Linearized Block Up-Converters (L-BUCs) Katalin Frolio, Student Member, IEEE and Allen Katz, Fellow, IEEE Abstract—This research project report includes the design, This signal can be used directly with a sub-harmonically analysis and experimental verification of Specialized Test pumped mixer, which internally doubles this frequency to the Equipment developed to support the production of Linearized desired 29 GHz LO frequency. 10 dB of attenuation at the Block Up-Converters (L-BUCs). L-BUCs are devices used to mixer’s input was used to minimize the effects of mismatch take base-band signals (typically in the 1 to 2 GHz range) and on the mixer’s performance. A block diagram of the mixer is up-convert them to microwave and millimeter-wave frequencies shown in Figure 1. (30 to 31 GHz in this application), and also linearize the converted signals to compensate for distortion introduced by post L-BUC power amplification. In order to test an L-BUC with a network analyzer where the port 1 and 2 frequencies are RF 30 - 31 GHz 10 dB Attenuators IF 1 -2 GHz at the same, a down converter is necessary. The goal of this work was to optimize an initial down converter design and to develop test equipment to support L-BUC production. 29 GHz X2 X2 Index Terms—block up converter, heterodyne principle, linearizer, monolithic microwave integrated circuit (MMIC), LO 7.25 GHz 14.5 GHz sub-harmonic mixer.
    [Show full text]
  • RF Manual 16Th Edition
    RF Manual 16th edition Application and design manual for High Performance RF products June 2012 NXP enables you to unleash the performance of next-generation RF and microwave designs NXP's RF Manual is one of the most important reference tools on the market for today’s RF designers. It features our complete range of RF products, from low- to high-power signal conditioning, organized by application and function, and with a focus on design-in support. When it comes to RF, the first thing on the designer's mind is to meet the specified performance. NXP brings clarity to every aspect of your design challenge, so you can unleash the performance of your RF and microwave designs. NXP delivers a portfolio of high-performance RF technology that allows you to differentiate your product – no matter where in the RF world you are. That’s why customers trust us with their mission-critical designs. Whether it’s LDMOS and GaN for high-power RF applications or Si and SiGe:C BiCMOS for your small-signal needs, we’ve got you covered. Our broad portfolio of far-reaching technologies gives you the freedom to design with confidence. Shipping more than four billion RF products annually, NXP is a clear industry leader in High Performance RF. From satellite receivers, cellular base stations, and broadcast transmitters to ISM (industrial, scientific, medical) and aerospace and defense applications, you will find the High Performance RF products that will help you realize a clear advantage in your products, your reputation, and your business. So if you're looking to improve your RF performance, design a highly efficient signal chain, or break new ground with an innovative ISM application, NXP will help you unleash the performance of your next-generation RF and microwave designs.
    [Show full text]
  • Raditek SATCOM Theory 101 Specifications May Be Subject to Change 04/01/17 WORLD HQ: 1702L Meridian Ave
    RADITEK INC. Introduction to Satellite Communications (101) A typical Raditek VSAT Dish directs the RF (via a power amplifier or BUC-Block Upconverter) to the satellite and receives (via an LNA or LNB-Low Noise Block downconverter or Amplifier) the signal from the satellite. Sizes can be from 1m to 1.8m for remotes. Hubs are usually much bigger. Modem- MODulates and DEModulates baseband data, on to / from an RF carrier that passes through the satellite. Common Satellite frequencies: C Band: typically 3.7 to 4.2GHz down link, 5.9 to 6.4GHz uplink. India (Insat) has a unique different set of bands. Extended bands are also used. Raditek SATCOM Theory 101 Specifications may be subject to change 04/01/17 WORLD HQ: 1702L Meridian Ave. Suite 127, San Jose, Ca 95125, U.S.A. Tel: (408) 266-7404 FAX: (408) 266-4483 WEB: www.raditek.com E-mail: [email protected] 1 of 14 RADITEK INC. X band for military Ku band 11.7 to 12.2GHz downlink, and 14-14.5GHz uplink. Ka band (new band over 20GHz) RAIN FADE: C band is used where rain fades are likely (as it is least effected by rain) eg Indonesia is almost totally C band Rain fade gets worse with frequency increase Ku band most popular, if rain fades are not high. Smaller antennas than C band. Ka band is newest band, with very small antennas, but high rain fades. SATELLITE: Acts as a repeater in space, Geostationary satellites are on the Clark belt, 22,000 miles above the equator.
    [Show full text]
  • Base Station Architecture Supporting On-Air Frequency Multiplexing
    Base station architecture supporting on-air frequency multiplexing Multi-channel digital TV and audio broadcasting systems (including SFN). Gained effect: The general system cost decrease, reliability increase and high noise immunity achievement. Group and single-channel transmitters. In modern digital TV broadcasting systems a transmitting over 100 TV programs is supposed. Most often used broadcast standards are DVB-T, DVB-C and DVB-S/S2. For multi-channel signals transmitting group transmitters which will convert generated on IF multi-channel digital signal to a radio frequency group signal and gain it on power for transmitting on-air through single omni-directional antenna or the sector antenna if radiation is made in a zone limited to some sector can be used. Much more attractive from the view point of a group signal formation convenience the method of its formation on intermediate frequency with the subsequent group spectrum conversion to a working radio frequencies range is represented. The method alternative to the given, is single-channel transmitters application, each of which will convert and gain generated on IF the separate channel signal. The signals received from N single-channel transmitters multiplexing on a radio frequency are carried out by means of the special multiplexer consisting from N channel BPF (bandpass filters) and the same number ferrite circulators (Fig. 1). Let's notice that both methods assume channels frequency multiplexing at physical level (PHY). Fig.1 Radio frequency multiplexor Let's consider the presented multiplexing methods merits and demerits from the view point of broadcasting complexes complexity and cost. For this purpose at first we will analyse the system consisting of the group transmitter and the omni- directional antenna.
    [Show full text]
  • 04-Gareth-Lloyd---Rohde-And-Schwarz
    LINEARIZATION OF RF FRONT ENDS Gareth LLOYD1 1 Rohde & Schwarz GmbH & Co. KG, Mühldorfstrasse 15, 81671, München, Germany Linearization, as a concept for improving signal integrity in radios, has been around for the best part of 100 years (at least dating back to Black's Feedforward patent, filed in 1920’s). A golden period of innovation followed for 80 years, until the turn of the century, when the now quasi- ubiquitous DPD (digital pre-distortion) became the architecture of choice. DPD has been widely adopted, no more so than in Mobile Communications – initially in infrastructure, more recently in mobile devices. The advent of 5G, with mm-/u-Wave implementations potentially enables alternative techniques. This paper provides a review of the subject matter, including; a linearization classification system, an overview of the limits and goals of linearization and a measurement example. ARMMS April 2017 | Gareth LLOYD page 1 Background The RFFE The RFFE (Radio or RF Frontend) is a PHY-layer concept (Figure 1). In the transmitter, the RFFE is responsible for conditioning (e.g. modulating, frequency shifting, filtering, amplifying) wanted data onto a carrier, suitable for transmission across a medium. In the receiver, the reverse operation. The RFFE, comprises a number of functional blocks, e.g. DAC/ADC, modulators, mixers, filters and amplifiers. The RFFE might be built with varying degrees of integration; monolithic, multi- chip module, or completely from discrete components. Figure 1 - Simplified architecture of transmit/receive frontend. This conditioning process, performed by the functional blocks, introduces errors; e.g. distortions and noise. Important macro parameters for the RFFE include operating power, efficiency, linearity and bandwidth.
    [Show full text]
  • RF Manual 17Th Edition Application and Design Manual for High Performance RF Products June 2013
    UNLEASH RF RF Manual 17th edition Application and design manual for High Performance RF products June 2013 www.nxp.com © 2013 NXP Semiconductors N.V. All rights reserved. Reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. The information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice. No liability will be accepted by the publisher for any consequence of its use. Publication thereof does not convey nor imply any license under patent- or other industrial or intellectual property rights. edition 53520-1305-1002 th Date of release: June 2013 Document order number: 9397 750 17428 Printed in the Netherlands RF Manual 17 NXP_06_0059_RF_Manual_17_Cover_Generic_v1.indd 1 03/05/13 16:15 NXP enables you to unleash the performance of next-generation RF and microwave designs NXP's RF Manual is one of the most important reference tools on the market for today’s RF designers. It features our complete range of RF products, from low- to high-power signal conditioning, organized by application and function, and with a focus on design-in support. When it comes to RF, the first thing on the designer's mind is to meet the specified performance. NXP brings clarity to every aspect of your design challenge, so you can unleash the performance of your RF and microwave designs. NXP delivers a portfolio of high-performance RF technology that lets you differentiate your product – no matter where in the RF world you are.
    [Show full text]
  • (12) United States Patent (10) Patent No.: US 7,911,400 B2 Kaplan Et Al
    USOO7911400B2 (12) United States Patent (10) Patent No.: US 7,911,400 B2 Kaplan et al. (45) Date of Patent: Mar. 22, 2011 (54) APPLICATIONS FOR LOW PROFILE (52) U.S. Cl. ....................................................... 343/713 TWO-WAY SATELLITE ANTENNA SYSTEM (58) Field of Classification Search ........... 343/711 713 (75) Inventors: Ilan Kaplan, North Bethesda, MD (US); See application file for complete search history. Mario Ganchev Gachev, Sofia (BG); Bercovich Moshe, McLean, VA (US); (56) References Cited Danny Spirtus, Holon (IL) U.S. PATENT DOCUMENTS (73) Assignee: Raysat Antenna Systems, L.L.C., 3,565,650 A 2f1971 Cordon Vienna, VA (US) (Continued) (*) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 FOREIGN PATENT DOCUMENTS U.S.C. 154(b) by 0 days. EP O572.933 12/1993 (21) Appl. No.: 11/647,576 (Continued) (22) Filed: Dec. 29, 2006 OTHER PUBLICATIONS (65) Prior Publication Data D. Chang et al., “Compact Antenna Test Range Without Reflector US 2008/OO18545A1 Jan. 24, 2008 Edge Treatment and RF Anechoic Chamber'. IEEE Antenna & Propagation Magazine, vol. 46, No. 4, pp. 27-37, dated Aug. 2004. Related U.S. Application Data (63) Continuation-in-part of application No. 1 1/320,805, (Continued) filed on Dec. 30, 2005, now Pat. No. 7,705,793, which Primary Examiner — Huedung Mancuso is a continuation-in-part of application No. (74) Attorney, Agent, or Firm — Banner & Witcoff, Ltd. 11/074,754, filed on Mar. 9, 2005, now abandoned, and a continuation-in-part of application No. (57) ABSTRACT 10/925.937, filed on Aug.
    [Show full text]
  • High-Efficiency Passive and Active Phased Arrays and Array Feeds For
    Brigham Young University BYU ScholarsArchive Theses and Dissertations 2015-11-01 High-Efficiencyassiv P e and Active Phased Arrays and Array Feeds for Satellite Communications Zhenchao Yang Brigham Young University Follow this and additional works at: https://scholarsarchive.byu.edu/etd Part of the Electrical and Computer Engineering Commons BYU ScholarsArchive Citation Yang, Zhenchao, "High-Efficiencyassiv P e and Active Phased Arrays and Array Feeds for Satellite Communications" (2015). Theses and Dissertations. 5741. https://scholarsarchive.byu.edu/etd/5741 This Dissertation is brought to you for free and open access by BYU ScholarsArchive. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of BYU ScholarsArchive. For more information, please contact [email protected], [email protected]. High-Efficiency Passive and Active Phased Arrays and Array Feeds for Satellite Communications Zhenchao Yang A dissertation submitted to the faculty of Brigham Young University in partial fulfillment of the requirements for the degree of Doctor of Philosophy Karl F. Warnick, Chair Neal K. Bangerter Brian D. Jeffs Michael A. Jensen David G. Long Department of Electrical and Computer Engineering Brigham Young University November 2015 Copyright © 2015 Zhenchao Yang All Rights Reserved ABSTRACT High-Efficiency Passive and Active Phased Arrays and Array Feeds for Satellite Communications Zhenchao Yang Department of Electrical and Computer Engineering, BYU Doctor of Philosophy Satellite communication (Satcom) services are used worldwide for voice, data, and video links due to various appealing features. Parabolic reflector antennas are typically used to serve a cost effective scheme for commercial applications. However, mount degradation, roof sag, and orbital decay motivate the need for beam steering.
    [Show full text]
  • MBT-5000A L-Band Up/Down Converter Revision 1
    MBT-5000A L-Band Up/Down Converter System Installation and Operation Manual Part Number MN-MBT-5000A Revision 1 Firmware Version 1.1.3 IMPORTANT NOTE: The information contained in this document supersedes all previously published information regarding this product. Product specifications are subject to change without prior notice. MBT-5000A L-Band Up/Down Converter Revision 1 Copyright © 2018 Comtech EF Data. All rights reserved. Printed in the USA. Comtech EF Data, 2114 West 7th Street, Tempe, Arizona 85281 USA, 480.333.2200, FAX: 480.333.2161 Revision History Rev Date Description 0 8-2017 Initial Release. 1 8-2018 Updated formatting and photos. MN-MBT-5000A MBT-5000A L-Band Up/Down Converter System Revision 1 TABLE OF CONTENTS PREFACE ...................................................................................................................................................... I 1.1 Conventions and References .......................................................................................................... i 1.1.1 Patents and Trademarks ................................................................................................................ i 1.1.2 Warnings, Cautions, and Notes ..................................................................................................... i 1.1.3 Examples of Multi-Hazard Notices ................................................................................................. ii 1.1.4 Recommended Standard Designations ........................................................................................
    [Show full text]
  • Gan Empowers Communication
    industry communications GaN empowers satellite communication GaN enables powerful, compact transmitters for demanding satellite communications BY MIKE COFFEY, STEVE RICHESON AND MICHAEL DELISIO FROM MISSION MICROWAVE 34 WWW.COMPOUNDSEMICONDUCTOR.NET l OCTOBER 2018 l COPYRIGHT COMPOUND SEMICONDUCTOR Mission MIcrowave v4RS 5MG.indd 34 26/09/2018 14:10 industry communications THROUGHOUT the history of radio communications engineers have craved more transmit power. This statement is as true today as it was in Marconi’s lifetime. One sector where there is a particularly strong desire for higher transmit power is satellite communications. Here high-power amplifiers and block upconverters have to generate signals that are powerful enough to offset path loss and spreading. In a traditional satellite communication link (see Figure 1), microwave- frequency radio signals are transmitted from a point on earth to a distant satellite in a geostationary orbit that is 35,000 km away – that’s a distance of almost six times the earth’s radius. The most common frequency domains for the satellite communications uplink are X-band (7.9-8.4 GHz), Ku-band (13.75-14.5 GHz), and Ka-band (29-31 GHz). Transmitter output power at these frequencies needs to be high, because satellites receive only a miniscule fraction of the power transmitted in their direction. Typically, a communications satellite may receive just a few picowatts of power from an earthbound transmitter that broadcasts tens of watts. A weak signal reaching the satellite’s receiver is not the only issue, however. That signal is coming from a single spot on the surface of the earth that could be masked by the background noise from our warm blue planet, alongside plenty of other potentially inferring signals.
    [Show full text]